You're listening to Brains On, where we're serious about being curious.
Hey friends, ever wonder how you're hearing me right now?
I mean, it's not like there's a tiny molly hidden in your speaker telling you stuff.
That would be weird.
Very.
But how is sound, like music or podcasts, recorded and played back?
We're going to surf a sound wave to find out.
Plus, we'll find out how microphones and speakers work, and meet a robot who has eaten several decades' worth of music.
It'll make sense in a minute.
Trust me.
So keep listening to Tiny Molly.
I mean, this podcast.
This is Brains On from the Brains On Universe.
I'm Molly Bloom, and today my co-host is Canyon from Montreal, Canada.
Hi there, Canyon.
Hi, Molly.
You know, Brains On is a rare thing these days.
A show made for kids and with kids and people all over the world.
Tune in to hear answers to the questions they send in.
We're also supported by people just like you who subscribe to our Smarty Pass.
When you subscribe, you get ad-free episodes, bonus content, live virtual hangs with Molly, Mark and Sandin and more.
Go to smartypass.org to sign up and make sure the show lives on.
Thanks.
So, Canyon, this whole episode is inspired by a question that you sent to us.
Yeah, I asked, how do they get music into CDs?
Tapes and records.
An excellent question.
Do you listen to music on all those devices?
Yeah.
My mom has a record player at my house and sometimes I listen to CDs in the car, but I don't really listen to tapes.
Okay.
So which kind of music would you say you listen to the most?
Like, which way of listening?
I usually listen to records the most, but CDs, I would say...
It's just sometimes I listen to CDs.
So when you listen to records, do you use the record player yourself?
No, it's usually my mom who just puts the record on and then starts it.
Then you rock out together?
Most of the times.
Nice.
So are you a headphone or a speaker person?
Like, how do you listen?
I would say I'm actually both.
Awesome.
So there are lots of ways to listen to music.
Like Canyon said, he listens to records, CDs. and on his tablet.
But in case anyone isn't familiar with CDs, cassette tapes and records, these are all examples of physical media.
Media is stuff like movies, music, and art, and physical means you can hold it.
It's not just something that lives on the internet or on your phone.
Here to tell us more about CDs and tapes and records is Robot Who Only Eats Physical Media.
Take it away, Robot!
Thank you, Mollybot.
Um...
I'm always not a robot.
Not a robot?
Then why is her head covered in coils?
They're adorable curls.
Curls, coils, potato, potato.
Anyway, yes it is I, robot who only eats physical media.
Why do I only eat physical media?
Because digital files give me robot gas.
Excuse moi.
Now I adore eating CDs.
Ha ha ha ha.
They are shiny flat discs about five inches wide, like a bagel.
They have a hole in the middle, also like a bagel.
And they play about 70 minutes of music, again, like a bagel.
Mmm, this Hootie and the Blowfish CD is divine.
But Mr. Robot, bagels don't play music.
What?
Then why do you eat them?
Um, because they're delicious food.
Meh.
Tomato, tomato.
I don't think you're using that saying correctly.
Why would I?
I don't understand human foods like potatoes or tomatoes or pinky toes.
My food is robot food, and the only robot food I'm interested in is physical media, remember?
Kind of hard to forget when your name is Robot Who Only Eats Physical Media.
Now, cassette tapes are a whole different snack.
Ha ha ha!
They are small plastic rectangles about the size of a deck of cards.
Inside the cassette there is a spool of brownish ribbon, kind of like a really thin roll of tape, but not sticky.
It's on that ribbon that the music is stored.
Oh my, so delicious.
Mmm, do you want a bite?
It's Madonna's Immaculate Collection on cassette.
No thanks.
I'm good.
The brownish ribbon stuck in my teeth.
Ah, there.
Got it out.
Any hoodle.
Moving on, we have vinyl records, or LPs, or as I call them, dinner.
These are large, black, flat discs about the size of a pizza.
But unlike pizza, they are delicious.
Actually, pizza is widely considered to be one of the world's tastiest foods.
But it's covered in cheese and tomatoes.
Yeah.
Now, if you squint your robot eyes, you'll see that records are covered in tiny grooves.
These grooves spiral from the outer edge of the record to the middle of it.
Believe it or not, it is in these grooves, in these little teeny bumpy lines.
That is where the music is stored.
It's also where the flavor is stored.
Mmm.
Miles Davis, you've done it again.
Another perfect meal.
Now, if you'll excuse me, dining on physical media is best enjoyed when it's like Harry Styles' career after One Direction.
Solo.
Ta-ta!
So CDs, cassettes, and records may be different shapes and sizes, but...
They're all just different ways to store music so you can play it back later.
So, Canyon, what songs have you been obsessed with lately?
I feel like I've been listening mostly just random AJR songs.
Random AJR songs, wonderful.
My house has been obsessed with K-pop Demon Hunter soundtrack.
I've been listening to that a lot, a lot, a lot.
So when you're listening to AJR songs, what do you usually do while you're listening?
I will usually play with my Lego, but when it's the right temperature, the right day and there's no snow outside, I will bring my iPad outside.
I'll bring some headphones, and I will play with my soccer ball while listening to my music.
That sounds very pleasant.
The ability to record and store sound has been around a long time.
Like around 150 years, which makes recorded music older than cars, home radios, and light bulbs.
But the way music is recorded is pretty much the same as it was back then.
Someone plays music.
The sound goes into a microphone and it gets sent to some kind of recording device that saves it so you can play it later.
More on that in a second, but as long as we're talking about playing sounds, let's play the Mystery Sound.
Alright Canyon, are you ready for the Mystery Sound?
Yes.
Okay, here it is.
What do you think?
I think it's like a trailer being hooked up to a car or a truck of some sort.
A trailer being hooked up to a car or truck.
That's a really good guess.
Should we hear it one more time?
Yeah.
Any new thoughts?
When I hear that, I feel like it's a machine of some sort or like my last answer.
Yeah, I like your guess of hooking up a truck or trailer.
It sounded definitely like metal to me.
I'm going to guess, because I have no idea what it is either, that it is a big metal pan and someone is putting it on a grate over a campfire.
I don't think that's right, but I'm just putting it out there.
You know, it's okay to be wrong.
We are going to hear the answer at the end of the show.
So stick around.
Hey friends, we've got an episode coming up all about skunks.
They're cute, they're cuddly, and they can stink.
But the stink is a defense mechanism.
That means it's a way for skunks to scare away animals that might hurt them, which is a pretty unique way to scare off your enemies.
So we wondered, if you could design a unique way to scare off animal enemies, what would it be?
What about you, Canyon?
What would your odd animal defense be?
An animal chore chart.
Tell me more.
Describe.
Um, a lot of chores to do.
And... something that either would get you wet to do something that you don't want to do.
I love that.
The animals would stay away because they're like chores a chore chart no, thank you, and they'd run away.
I love that idea.
Very, very clever.
Listeners, share your ideas for a wild animal defense mechanism by going to brainsonorg slash contact.
While you're there, you can also send us your drawings and questions.
That's BrainsOn.org.
And keep listening.
You're listening to Brains On.
That's Molly.
And I'm Canyon.
And we're talking about how music is recorded and played.
So when you record music, it's the same.
Hold on a sec.
Jack and Sandin, do you have to make all this racket while we're taping?
Oh, hey, Molly.
Perfect timing.
I'm helping Sandin record the new band he's managing.
New band?
You know how everyone's always saying, I love heavy metal, but I wish there were more poodles in it.
Oh, yeah.
Yes, uh-huh, sure.
That's definitely something I've said.
Well, this is the world's first all-poodle heavy metal band.
Meet Penelope and the Poodles.
Wow, Penelope can shred the guitar.
And I didn't know dogs could hold drumsticks like that.
Shh, Molly, don't say ixtay.
Ixtay?
You mean stick?
No, leave it.
Bosco, leave it, leave it.
Nope, nope, we're not playing fetch.
That's for Tina's drums.
The poodles are easily distracted.
But hey, I figured since you and Canyon were learning all about music, we could help.
I got the atom here.
And it's ready to go.
Oh, sweet.
The Atom, which stands for Amazing Truck of Minimization.
Yep, our shrinking vehicle.
Hop in, and the Atom will shrink us down so we can follow a song as it gets recorded and stored.
Yay!
I was hoping I'd get shrunk today.
Otherwise, this shirt I wore would make no sense.
You mean the shirt that says, Yay, I got shrunk today?
Yep, wearing it when you don't have plans to shrink is a bit of a gamble, but sure paid off today.
All right, let's get Minnie and take a spinny.
Just give me a second to calibrate the micro-engines and... Ah, there.
Sandon's going to stay behind and direct the band.
Okay, Penelope and the poodles, ready to rock?
No, no, I said rock, not walk.
Ugh.
Get back to your instruments.
Go up.
Good dogs.
Good dogs.
Okay, now sit.
Stay.
Slay.
Okay, Molly and Canyon.
Hold on.
Shrink mode activated.
I love this part.
Why is my underwear shrinking faster than the rest of me?
Ooh, tight.
Whoa.
Whoa.
We're micro-sized.
It sounds different from down here.
Yeah, we're so small now we can surf a sound wave.
Sound waves are how sound travels.
When Bosco strums her guitar, the air around the guitar strings vibrate or wiggle.
And the way it vibrates is the wave's pattern.
The wave travels from the guitar strings to our eardrum and makes our eardrum wiggle or vibrate in the very same pattern.
And then our brains take that vibrating pattern in the eardrum and translate it into sounds that we hear.
So those rushing sounds, I mean, those are sound waves or waves of air?
Exactly.
That's the sound from Penelope and the Poodles rocking out.
Now, when you're recording music, you need microphones to record those waves of air.
Like that microphone there.
Cool.
The waves of sound are carrying us toward the microphone.
We're heading straight to it.
We'll be smashed to pieces.
Don't worry.
There are tiny holes in the microphone, and we'll be fine if I can steer just right.
There.
Now we're inside the microphone.
Doggy, that was close.
I need a minute to settle my nerves.
Understandable.
Let's all take a breather while I go check on the microcity meters.
BRB.
Cool.
Seems like a good time to check the mailbag.
Yeah.
We get a ton of email and actual paper mail from you all.
And since we've been moving headquarters, it's really piled up.
Sandin's been going through it piece by piece.
So let's check in with him.
Time for the mailbag.
I love all this mail.
Okay, let's see.
Oh, I'm going to open this letter.
Ooh, it's a drawing of Gungador.
Looks perfect.
Okay, let's see.
Oh, I'm going to open this email.
Ooh, it's a bill.
Wait, that's not fun.
I'm just going to forward that one to Molly.
Let's see.
Oh, check it out.
We got a message from a teacher.
Let's give it a listen.
Hi, my name is Carla Morin.
I'm a third grade teacher in Canton, Michigan.
I love to use the Brains On podcast with my science classes.
I match up episodes with science units like Life Cycles and Traits.
For the Traits unit, one of my favorite episodes is Meet Sandy the Left-Handed Mutant Snail.
It's something that kids can relate to, being right or left-handed.
As a science teacher, I like that it features school kids as scientists.
In the episode, it's a student who discovers a sinistral snail.
My students love the voices of the snail and the sound effects and the fact that it also talks about mutants.
As a science teacher, I love all the questions that Brains On asks and it gets kids to think about science and be interested in science.
Oh, I love to hear it.
Thanks for sharing us with your class.
I'm sending you a free Smarty Pass subscription.
Enjoy.
If you use Brains On in your class, let us know about it.
Oh, check it out.
Another email from Molly.
Let's see what it says.
Sandit, stop forwarding me the bills for all the snake food you keep buying.
You don't even have a snake.
Signed, Molly.
Hmm.
Fair point.
I don't have a snake.
Yet.
But when I do, it'll eat well.
Okay, well, send us your drawings, life questions, or designs for a new room at Brains On HQ.
Just go to brainson.org slash contact.
Bye!
This is Brains On.
I'm Molly.
I'm Canyon.
And I'm Mark.
Molly, Canyon, and I are in our incredible shrinking truck called the Atoms.
We've shrunk down and we're inside a microphone.
Now, every microphone has something inside it that sound waves can run into.
And if you look just ahead right over there, you'll see that this one has a tiny little plate.
It's called a diaphragm.
Whoa, neat.
The waves of air are making that diaphragm plate thing vibrate and wiggle in a pattern too.
Is that like how the sound waves of air vibrate?
Make our eardrums wiggle?
Yes, yes, exactly.
Think of the inside of a microphone like a machine version of your eardrum.
It's listening to music, except in your ear.
Your brain turns the wiggles of air into a message for your brain and your brain interprets that message as sound.
In the microphone.
That wiggling plate turns the airwaves into an electric signal and that signal is sent through a microphone cable to a machine where it's stored.
Wait, we're heading right towards the vibrating plate.
Does that mean the microphone is going to turn us into an electrical signal, too?
Oh, no.
We'll be fine, I think.
Or we might get turned into a pure form of energy that can neither be contained nor measured.
Oh, that's bad.
Why did I wear these socks?
That say yikes.
I got turned into a pure form of energy that can neither be contained nor measured.
Where do you shop for clothes, Molly?
Hold on to your seats, people.
Here we go!
I can't believe it.
I mean, despite not knowing what I was doing, we're totally fine.
And I can't believe I wore underwear that says, despite not knowing what I am doing, I am totally fine.
To be fair, all of my underwear says that.
Despite not knowing what I'm doing, I am totally fine is kind of my life motto.
Wow, I can't believe what I'm seeing.
Mark, what am I seeing?
Oh, that's the electrical current inside the microphone cable.
The sound waves from before have now turned into patterns of electricity.
It's wild to me that sound can be turned into electricity.
I know.
It's all about keeping the same pattern.
You see, sound waves are just a pattern of waves that push and pull on air.
Some waves are big.
And some are small.
Some are short and fast.
And some are long and slow.
All those things make the waves of air sound different to your ear.
Microphones just take that same pattern and write it as electrical pulses.
So the pattern was like a coat.
The same information, but stored in a different way.
Yes, yes, yes, yes, yes.
Exactly like code.
All through the process of recording and playing music, that pattern from the waves of air is turned into different codes.
Sometimes it's electric code.
Sometimes it's digital code.
But it's always the same pattern.
And guess what?
We're here!
Technically, wherever you are is here, Mark.
Can you be more specific?
Good one, Molly.
But we're in the recording equipment.
It's the place where the sound from the microphone is stored so you can use it later.
Oh, cool.
So the sound is another code now?
What kind of code is it this time?
Well, in the olden days you might churn those electrical signals from the microphone into a code on a special kind of audio tape.
These days, the electrical signals are usually churned into a code that computers read.
So we're in a computer right now?
You betcha.
That's amazing.
What are the odds?
Let me guess.
You have a hat or a handkerchief or something that says, Wow, I'm in a computer?
No.
I just think it's amazing we are in a computer.
But note to self to make that hanky my next crafting project.
Anywho, after all the music is recorded and saved here, then it can be turned into an audio file.
Huh.
And I'll bet that master file has the same pattern as the original sound wave, but just in a different code.
So the music went from sound waves in the air into a microphone, where it became electrical signals.
Then it traveled through a cable to a recording machine.
From there, it can be put onto a CD or tape or whatever.
Perfecto correcto!
Now let's unshrink and get out of here before some antivirus software in the computer finds us and tries to delete us.
Yikes!
Whoa!
Why is my underwear not unshrinking fast enough?
So tired again.
Good to be me-sized again.
For sure.
So Mark, after the music is made into a master file, how does it get on different things like tapes or CDs or records?
Well, there are special machines that take the code from the audio file and turn it into yet another code.
And that is put on the physical media.
Tapes, records, and CDs, they all store that pattern, but just in different ways.
That's right!
And here to tell us more is me, robot who only eats physical media.
Thank you, Molly Canyon and Third Human, whose name I don't know.
It's Mark!
Unimportant.
What is important is that I enjoy eating physical media, like a CD.
Now, you can't feel it with your robot tongue, but inside a CD is a thin aluminum disc.
And the pattern or code for the music is written on that disc.
When you play a CD it spins and a little laser reads that code and turns it back into an electrical signal.
Like the one the microphone made?
Yep, exactly like that, Canyon.
But this time, that electrical signal is sent to a speaker.
Speakers take the electrical codes and turn them back into sound waves.
How do they do it?
Inside a speaker, there's another kind of plate, like the one we saw on the microphone.
The electrical signals make it wiggle in that same pattern as the original sound.
And as it wiggles, it pushes on the air around it, creating... Sound waves.
So a speaker is just a fancy way to turn that electrical signal back into a wiggling wave of air that you can hear.
Ding, ding, ding.
Exactly.
Yes.
Now back to me.
CDs store their code on aluminum discs.
Cassettes store it on that spool of tape inside the cassette.
This time, it is a magnetic code.
Magnetic.
Nom, nom.
Nom, delicious.
And again, a tape player reads the magnetic code on the tape and turns it back into an electrical code which is sent to a speaker.
And turned back into a sound wave.
I get it now.
And finally, we have records, like this limited edition version of Taylor Swift's Reputation.
Here, the music's code is stored as little bumps inside those tiny grooves.
A very small needle rides on those grooves as the record spins.
The needle helps turn that code back into an electrical signal which goes to a speaker, and you know the rest.
The important part is...
That you thoroughly chew your record so you don't choke on look what you made me do.
Taylor's version really does taste better.
Hey, guys.
Did you get the recording of the poodles?
Sure did, buddy.
And it sounds great.
Combining poodles and metal was a truly inspired idea.
Oh, totally.
By the way, has anyone seen my tape CD and record collection?
They aren't in my tape CD and record bin.
Oh.
And look at what the time is.
I have to go for reasons completely unrelated to what he just said.
Bye.
Sound is just patterns of wiggling air.
When you record music, it goes into a microphone, through a cable, into a machine where it is recorded.
Then you can put the music on a CD, a cassette tape, or a vinyl record.
When you play music, it goes into a speaker.
The speaker wiggles the air to make sound waves.
Then your ears hear those sound waves, and that's how you hear music.
That's it for this episode of Brains On.
This episode was written by Shannon Totten.
It was edited by me, Molly Bloom, sound design by Rachel Brees, and mixed by Mark Sanchez.
He also wrote our theme music.
Special thanks to Anna Winters, Steven Winters, and Blake Iverson.
Many thanks to Ken Taborski and Code of the North for all their website help.
Brains On is an independent podcast.
Our show depends on your support.
Help the show grow by going to BrainsOn.org and sign up for Smarty Pass.
That's our ad-free feed where you get discounts on merch and live events.
Plus hangs with Sandon, Mark, and me.
Get good stuff for supporting good podcasts.
Totally.
Sign up today at brainson.org.
Now, before we go, let's take one more pass at that mystery sound.
What do you think?
Last time you thought maybe a trailer getting hooked up.
Some kind of machine.
I thought something with like a pan.
I don't think that's right anymore.
What do you think?
Any new thoughts?
I feel like I'm going to stick with my thought.
Your trailer thought?
I think it's a good one.
I think it's the inside of a pinball machine and someone is fixing it.
All right.
Let's hear the answer.
Hello, my name is Sophie from Arlington Massachusetts, and the sound that you just heard was me opening and closing the flue of my fireplace.
Oh, the flue of a fireplace.
Can you hear that now that we know?
Mm-hmm.
It was metal, so we were both a tiny bit right.
Do you have a fireplace?
I used to.
Mm-hmm.
Yeah, so the flu is something inside the fireplace that, like I think, lets the air in and out.
I think.
Oh, that was a tricky one.
They stumped us.
Now it's time for the Brain's Honor Roll.
These are the incredible kids who keep the show going with their questions ideas, mystery sounds, drawings and high fives.
Sam from Guelph, Ontario, Eli from Delaware, Vera from Herndon, Virginia, Jack and Noah from Mercer Island, Washington, Alice and Elijah from Robbinsdale, Minnesota, Dex from Portland, Oregon, Archie from Carmel, California, Emmett from Waynesboro, Virginia, Isla from Wyoming, Lucy from New Plymouth, New Zealand, Bethany from the UK, Hunter from Kincan, Australia, Luca and Wyatt from Pennsylvania, Fiona from St.
Louis, Walter from Great Falls, Montana Ivy from Cincinnati, Miles and Dylan from Taipei, Taiwan.
Anderson from Leipzig, Germany.
Avery and Andrew from Knoxville, Tennessee.
Kian from Bloomington, Indiana.
Brooke from Apollo Beach, Florida.
Amelia from Litchfield, New Hampshire.
Shane and Kevin from Marlton, New Jersey.
Montgomery from Vineyard Haven, Massachusetts.
Finn from Altoona, Pennsylvania.
Eddie, Rocky, Ray, Lou, and Daphne from Austin, Texas.
Jacob from Plantation, Florida.
Donovan from Mesa, Arizona.
Addie and Elise from St.
Louis.
Riley from Los Angeles.
Paloma and Martina from San Jose, California.
Karim from Manchester, United Kingdom.
Edith from Kansas City.
Etta from Murfreesboro, Tennessee.
Bonnie from Whitehorse, Yukon.
Eleanor from Lake Oswego, Oregon.
Stella Thank you.
Juana and Serene from Dubai, Ashwini from Dallas-Fort Worth, Lila from Stevensville Maryland, Mia from Chilliwack, British Columbia, Jack from New Hampshire, Alistair from Halifax, Nova Scotia, Anthony Wesley and Richard from North Carolina, Jordan from Colorado, Richard from Norfolk, Virginia Olin from San Francisco, Theo from Port Macquarie Australia Isabella, Isaac and Max from Basel Switzerland, Logan from Bakersfield Florida, Camilla from Longwood Florida, Juniper and Porter from Newport, Washington and McKenna from Flemington, New Jersey.
Tune in next week for more answers to your questions.
And thanks for listening.
